Silica is refractory so the glaze will run less. The Gerstley Borate is a natural source of boron (with issues frits do not have). After firing the catch plate is removed and the bottom is ground to a nice finish. Feldspar and talc are both flux sources (glaze melters). Its high-sodium makes it high thermal expansion. When two are similar we can see it immediately. 3195 is looking very well behaved compared to most others, forming a bubble free glass of high surface tension (F15 and F524 are starting to do the same). The crazing is because of high KNaO (potassium and sodium from the high feldspar). Ferro Frits 3110 High Soda Frit . But a high MgO frit is melting beautifully at cone 06. These contain boron (B2O3), it is magic, a low expansion super-melter. Frits melt really well, they do not gas and they have chemistries we cannot get from raw materials (similar ones to these are sold by other manufacturers). Since it is somewhat soluble some precipitation can occur in glazes stored for lengthly periods. I have done alot of work recently comparing the sourcing of fluxing oxides from frits vs. raw materials. Frit 3134 is still expanding. Copyright © 2020 New Mexico Clay, Inc      All rights reserved. LA300 and Frit 3124 are starting also. Try layering the glazes, as opposed to mixing the oxides, for interesting varied colors. Of course, glaze chemistry is needed to calculate how to do this, there are videos at digitalfire.com on how to do this. Powered by NitroSell{lang: 'en-GB', parsetags: 'explicit'}. Some are still burning off carbon (which seems strange). They are made from 80 Redart, 20 Ball clay. But it got "smoked" by the Fusion FZ-16 high-zinc, high-boron zero-alumina! As high as cone 6, talc (the best source of MgO) shows no signs of melting activity at all. It will also fire more durable and be more resistant to leaching. This is an 85% fritted glaze, yet it still has carbon - think of what a raw glaze might have! The latter is the most transparent and brilliant, even though that frit has high MgO. Of course, these specimens test a very thick layer, so the bubbles are expected. In addition you will be able to reduce the amount of troublesome calcium carbonate. Fired at 350F/hr to 1800F and held for 15 minutes (I already did firings from 1300F-1750F in 50 degree increments, all of them are visible in the parent project). 3195, F38 and F15 are softening. It works in bodies and is great to incorporate into glazes that shiver. 3602 and FZ16 are really starting to move. Manganese Dioxide 1% to 4% for lavender on tan. Great for old fashion bristol glazes. Firing: In general fire to cone 10, cool the kiln to 2000 degrees and hold for 3 to 5 hours in-between 2000 and 1800 degrees. This is a testament to the utility of Redart at low temperatures.